Improvement in buhl-saws



llttrti tctrn @met -diiiillf :THOMAS LEAVITT, or nvnnnrr, ASSIeNOn froSORRENTO woon-canv- :INGS COMPANY, OFBOSTON, MASSAOHUSETTS.

Lettere Patent No. 110,051, aetea neeember 1s, 1870.

lmrnovsmsm* IN BuHL-sAws.

The Schedule referred to in these Letters Patent and making part of thesame.

To all whom it may concern Be it known that I, THOMAS LEAvITT, ofEverett, in the county of Middlesex, and State of Massachusetta, haveinvented an Improvement in Buhl-Saws; and I do hereby declare that thefollowing-taken in connection with the drawing which `accompanies andforms part of this specification, is a description of my inventionsuioient to enable those skilled in the art to practice it.

My invention relates particularly to a method of 'clamping the ends ofsmall ne saws, like hand-operated buhlsaws, in their frames.

.The ends of these saws, and of most ne dat saws or jig-saws, areconfined between clampplates,`which are tightened upon the saw bya screwand nut, the screw extending from one plate through the other, whichother is forced toward the rst by the nut working over the screw-thread.For very fine saws these clamp-plates are objectionable, and do notclamp the saw sniciently tight vto prevent its slipping,

In my invention I employ for each end of the saw a clamppin having adiametric slit, and formed with along conical taper between the head andshank, the incline or tapering portion of the head passing through andresting on a bearing-plate orseat fixed to the arm of the ksaw-frame,-while thev shank ofV the pin, which is screw-threaded, passes throughsaid arm.

On the outer side of the framea nutworks upon the screw, and bytightening this nut' the tapering head of the clamp-pin is drawn intothe bearing-plate, the hole through which, being smaller than the outerend of' the head, causes the two parts of the head to be forced tightlyagainst vthe saw, clamping it securely in position.

The invention primarily consists in this method of clamping a ,s'aw, andin making each clamppin with a key or spline, which, entering a notch inthe bearing-plate, prevents any rotative movement of the saw.

The drawing represents a saw-frame having a lSaw clamped in accordancewith my invention, and thedetails, A, B, andgG, show one of theclamp-pins and seat or bearing-platein full size.

a l? denote the two bars of the saw-frame, connected by the strut orcross-bar c.

d is the straining-rod, which, by means of a screwthreadfe, cut upon it,and a nut, iv, draws the outer ,Y endsl of the bars a b'inward, and=forces the opposite f ends of the bar outward, thereby stretchingorstraih ing the saw o extended across between the two bars.

0n the inner side ot' each bar a l),y at the saw-holding ends thereof, aplate, f,'is fastened, eheh plate f having a conical hole madethroughit, through which two holes and holes bored through the bars al), inline therewith, the clamp-pins y are passed.

The head of each pin has a conical taper, as seen at 71, the conicalpart resting iu its plate f, and each head is slit diametricaliy, asseen at t', and Ato s uch distance into the pin as to permit theopposite parts of the head to be pressed together.

The screw-threaded shank of each piu v passes through and projectsbeyond the frame-bar a or b, and a nut, It, works upon said thread, thenut bearing against the bar or upon a suitable washer, and, by its'rotation, drawing the head of the screw more or less int-o the plate f.

Into the slits of the two clamp-pinsA the opposite ends of th-e saw arethrust, (the clamp-pins being first loosened by the nuts,) and, by thenturning up the nuts, the conical heads are forced into the plates,thereby pressing Athe two parts of each head tightly upon the saw, sothat it cannot possibly slip trom position at either end. 'lo preventthesaw from turning or twisting, cach clamp-pin is made with a spline orkey, l, that, entering a slot, m, in the plate f, fastens the key, sothat while it can slide endwise it cannot move rotatively.-

In all hand-worked bnhl-saws, and similar sawsY heretofore made, the sawhas been in axial line with the center of the handle, but in my saw Iplace the nut and clamp-pin (adjacent to the handle) in lihe withthesaw, and fasten the handle u to the barof the sawframe, on one sideof the nut and pin, thus leaving thc nut at all times accessible, totighten or loosen the clamp-pin.

I claim- In combination with thc Saw and saw-frame, the

Witnesses; 'rHoMAs LEAvrr'r.

FRANCIS GOULD, J. F. BEALE.

